Answer:
Rational and integer i.e option A and C
Why did you circle all of them ?
Answer:
There is not sufficient evidence to support the claim that the technique performs differently than the traditional method.
Step-by-step explanation:
The null hypothesis is:

The alternate hypotesis is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
A researcher used the technique with 260 students and observed that they had a mean of 94 hours. Assume the standard deviation is known to be 6.
This means, respectively, that 
The test-statistic is:



The pvalue is:
2(P(Z < -2.69))
P(Z < -2.69) is the pvalue of Z when X = -2.69, which looking at the z-table, is 0.0036
2*(0.0036) = 0.0072
0.0072 < 0.01, which means that the null hypothesis is accepted, that is, there is not sufficient evidence to support the claim that the technique performs differently than the traditional method.
Mx - y
5x-y
5(3)-y
15-y
15-8 = 7
7 is your answer.
Let the two numbers be x and y where x is greater than y.
So;
x + y = 3.1 ... (i)
2x - 3y = 7 ... (ii)
This forms a set of simultaneous equations (i) and (ii)
Solving the simultaneous equations by elimination;
We multiply (i) by 2 and (ii) by 1 to get:
2x + 2y = 6.2 ... (i)
2x - 3y = 7 ... (ii)
Subtracting (i) - (ii) we get;
5y = -0.8
y = -0.8/5 = -0.16
x = 3.1 - -0.16 = 3.26
The numbers are 3.26 and -0.16.